release: v0.3.0

47 deep reviews, 273 tests, hardened codebase.

Highlights since v0.2.0:
- fix: treat arguments null as absent in tools/call (DR46-H1)
- fix: cached tools/list via OnceLock, indexed field in send_message (DR45)
- test: 15 new regression tests (DR45-DR47)

Co-Authored-By: Claude Opus 4.6 <[email protected]>

v0.2.0 — Hardened Release

31 adversarial deep reviews, 195 unit tests, ~130+ issues fixed.

Highlights:
- Complete input validation on all 4 MCP tools (create_agent, send_message, get_inbox, search_messages)
- JSON-RPC 2.0 spec compliance (notifications, error codes, version validation)
- Schema-runtime consistency (tools/list schema matches runtime behavior)
- Validation deduplication: validate_text_core() / validate_name() / validate_text_field()
- Hot-path optimization: zero unnecessary allocations on broadcast sends
- Concurrency hardening: atomic entry()-based DashMap operations, TOCTOU race elimination
- Defense-in-depth: path traversal protection, inbox caps, agent/project limits